The present invention relates generally to methods and apparatus for actuating an aircraft nose portion. Some conventional transport aircraft have nose portions that move relative to the rest of the aircraft. For example, the European Concorde supersonic aircraft has a nose portion that droops downwardly during approach and landing to give the pilot increased downward visibility when the aircraft is at a high angle of attack. Other aircraft have nose portions that move to allow access to the interior of the aircraft. For example, the Lockheed C-5 aircraft has a nose portion that swings upwardly to open the fuselage for loading and unloading. Other aircraft, such as those disclosed in U.S. Pat. Nos. 3,150,849; 4,116,405; and 4,379,553 disclose nose portions that swing to the side to allow access to the aircraft interior. However, none of the foregoing designs address the issues addressed by the present invention.
The present invention is directed toward methods and apparatus for actuating an aircraft nose portion. An aircraft in accordance with one aspect of the invention includes a fuselage having a longitudinal axis and a pitch axis generally transverse to the longitudinal axis. The fuselage can include a pressure bulkhead, a pressurized payload portion aft of the pressure bulkhead, and a nose portion forward of the pressure bulkhead. The nose portion can be pivotable relative to the pressurized payload portion about a pivot axis generally parallel to the pitch axis while the pressurized payload portion is capable of being pressurized relative to a region external to the aircraft. The nose portion can be pivotable between a first position and a second position, with the nose portion being generally aligned with the longitudinal axis when in the first position, and with the nose portion being inclined upwardly relative to the longitudinal axis when the nose portion is in the second position.
In another aspect of the invention, the aircraft can include a pivot support member projecting forward from the pressure bulkhead, with the pivot support member being received in a corresponding slot of the nose portion. A pivot pin can be pivotably coupled between the pivot support member and the nose portion, and an actuator can be operatively coupled to the nose portion to move the nose portion between the first and second positions.
In yet a further aspect of the invention, the nose portion can change from a first configuration with the nose portion and the fuselage having a combined first length to a second configuration with the nose portion and the fuselage having a combined second length of about 5 percent or more shorter than the first length. For example, the nose portion can pivot between the first and second configurations. In still a further aspect of the invention, the nose portion can be inclined upwardly at an angle of approximately 90 degrees relative to the longitudinal axis when it is in its second configuration.
The present invention is also directed toward a method for reducing a length of an aircraft during operation. The method can include flying the aircraft while the aircraft has a first length, landing the aircraft, and pivoting a nose portion of the aircraft upwardly to reduce the length of the aircraft to a second length. The method can further include moving the aircraft with the second length relative to an unloading area, and unloading the aircraft at the unloading area only through one or more openings that are spaced apart from the nose portion.
A method in accordance with another aspect of the invention includes at least partially sealing a pressurized portion of an aircraft fuselage so that the pressurized portion is capable of being pressurized relative to a region external to the fuselage. The fuselage can have a longitudinal axis and a pitch axis generally transverse to the longitudinal axis, and the method can further include pivoting a nose portion of the aircraft relative to the pressurized portion about a pivot axis that is generally parallel to the pitch axis. Pivoting the nose portion can include pivoting the nose portion from a first position with the nose portion generally aligned with the longitudinal axis to a second position with the nose portion inclined upwardly relative to the longitudinal axis while the pressurized portion is capable of being pressurized relative to a region external to the fuselage. In a further aspect of the invention, the nose portion can be pivoted downwardly while the aircraft is in flight or in preparation for flight.